While at Texas, Sauer played as a wide receiver, catching passes from quarterback Jim Hudson. After being teammates as Texas, Hudson and Sauer would continue as teammates for the New York Jets for five years from 1965 through 1969.

Sauer retired at the peak of his career following the 1970 season because he considered professional football dehumanizing.[2] In a 1971 interview with the Institute for the Study of Sport and Society, Sauer said, "When you get to the college and professional levels, the coaches still treat you as an adolescent. They know damn well that you were never given a chance to become responsible or self-disciplined. Even in the pros, you were told when to go to bed, when to turn your lights off, when to wake up, when to eat and what to eat. You even have to live and eat together like you were in a boys’ camp."[2] Sauer's father, on the subject of his son's retirement, stated, "He definitely does not like to be regimented."[2]

In spite of his disillusionment about playing professional football, Sauer returned to play for the New York Stars of the World Football League in 1974. That season Sauer caught 38 passes for 547 yards, good for 14.4 yards per catch and 3 touchdowns.